Brieane Olson can now add author to her résumé. The chief executive officer of Pacsun, the California-based specialty retailer, has penned her first book : “Co-created: The Cultural Strategy That Redefined Pacsun .” The book traces how Olson, who joined the retailer in 2007 and was elevated to the top post in 2023, transformed the company by embracing its Gen Z consumer base. Her strategy is centered around building what she describes as a “purpose-driven” company at the intersection of fashion, music, art and sport — all categories important to today’s youth. Under her leadership, Pacsun has collaborated with everyone from Formula 1 and the Metropolitan Museum of Art to Yohji Yamamoto, Selena Gomez, A$AP Rocky and Fear of God’s Jerry Lorenzo, positioning the retailer for success while many of its teen-oriented competitors have struggled or disappeared. Pacsun nearly went down the same path.…